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Received: from willy by casper.infradead.org with local (Exim 4.98.2 #2 (Red Hat Linux)) id 1vya6m-0000000H9Eb-2cL2; Fri, 06 Mar 2026 18:41:08 +0000 Date: Fri, 6 Mar 2026 18:41:08 +0000 From: Matthew Wilcox To: Kiryl Shutsemau Cc: Chris J Arges , akpm@linux-foundation.org, william.kucharski@oracle.com, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, kernel-team@cloudflare.com Subject: Re: [PATCH RFC 1/1] mm/filemap: handle large folio split race in page cache lookups Message-ID: References: <20260305183438.1062312-1-carges@cloudflare.com> <20260305183438.1062312-2-carges@cloudflare.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Rspam-User: X-Stat-Signature: d6iw4t6ei1ratxokqychzw4kxf4afw1s X-Rspamd-Queue-Id: 569A5C0002 X-Rspamd-Server: rspam03 X-HE-Tag: 1772822473-662764 X-HE-Meta: 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 2JSB9UtH Kea31Y6+xXxWc4HgYLZ/oAnT0BxwjJUFxZrz6OIHTv9dSvwYyYlHYzfRRwxeRcm4/eH0b1VhVVeYnZwSJP3FMhqPZPLXE4s8uZ9xcT09pjlMVfXV+8JSpPBECigSaMeB5uKViGoQlVn82xR1tbpyiLzjBhuD7E4mnBiZBN/PseEaXHM640AGrSB0v8hlYlQN3bG9lGcXOYXaP3Rm7kxVuiUR8RU1h8vLuo3QmVrMMJRu2spXznz9eiFiJeA== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Fri, Mar 06, 2026 at 06:36:30PM +0000, Kiryl Shutsemau wrote: > The proposed change doesn't fix anything, but hides the problem. > It would be better to downgrade the VM_BUG_ON_FOLIO() to a warning + > retry. The trouble is that a retry only happens to work in ... whatever scenario this is. If there's a persistent corruption of the radix tree, a retry might be an infinite loop which isn't terribly helpful.